Compostable lid intended to seal a capsule and a capsule sealed by the lid

ABSTRACT

A compostable lid intended to seal a beverage capsule is provided. The lid is composed of a multilayer complex successively comprising a non-woven material wherein at least 50% by weight of the fibers are composed of polylactic acid (PLA), an adhesive layer suitable for coming into contact with food, and a support layer composed of a vegetable parchment.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This patent application claims priority to French national applicationFR1653909, filed Apr. 29, 2016.

FIELD OF THE INVENTION

The invention concerns a lid intended to seal a capsule, particularly ofcoffee. An object of the invention is also a capsule sealed by said lid.Finally, it concerns the utilization of said lid for sealing a capsulecontaining a food product, particularly ground coffee.

In the following description, the invention is described in relation tocapsules of coffee. However, it is applicable to all domains in whichthe lid can be used to enclose food substances and it must be waterresistant, pressure resistant, resistant to tearing, and advantageouslyheat-sealable onto a capsule or anything else containing food. Morespecifically, this invention applies to a compostable lid intended toseal a capsule containing a dry powder (e.g. coffee, tea, hot chocolate,etc.) for making a beverage.

BACKGROUND OF THE INVENTION

Coffee pods available in the market generally contain about 5-15 g ofground coffee. The amounts are less for tea on a mass basis, althoughthe volume of material for infusion is generally comparable. Percolationtime of the coffee machines is typically 10 to 60 seconds for a watervolume ranging from as low as about 30-40 ml for espresso capsules toabout 120-300 ml for drip coffee capsules.

In the food industry, the materials used are regularly subject toincreasingly stringent requirements especially regarding environment.Thus, the currently developed products have no longer the sole objectiveof meeting consumer's tastes. They must also meet the requirementsrelating to the respect of the environment. These requirements may beregulatory, and may also reflect evolving consumer preferences forreusable, recyclable, or degradable products.

Two types of coffee pods are currently offered on the market, namely:

-   -   flexible pods composed essentially of a sachet of non-woven        material containing the coffee,    -   rigid pods or capsules composed of an actual capsule closed by        means of a lid.

The invention specifically concerns the capsules.

Generally known on the European market are capsules of the NESPRESSO®type. Such capsules are described, for example, in U.S. Pat. Nos.7,153,530 and 7,658,141. These capsules are typically provided with afrustoconical side wall and dish-shaped bottom formed of aluminum(20-100 μm), a pure or multilayer plastic, a cardboard/aluminum/plasticcomposite, or a cardboard plastic composite. A layer of a fabric such aspolyurethane is provided at the bottom of the capsule to filter coffee.The cover of such Nespresso® capsules may be formed from a variety ofmaterials, such as aluminum or a multi-layer composite comprising paper,aluminum and/or plastic (e.g. polypropylene (PP), polyethylene (PE),polyamide (PA), polyethylene terephthalate (PET), ethylene vinyl alcohol(EVOH), polyvinylidene chloride (PVDC), etc.).

Typically, the circular cover is heat-welded or crimped to the peripheryof the capsule side wall. However, there is a strong demand to transformthese non-compostable capsules into compostable capsules.

Additional features of NESPRESSO® capsules are described in U.S. Pat.No. 8,956,672, which discloses capsules having an inverted cup-shapedbody with a sidewall and a truncated bottom injection wall collectivelydefining a chamber, and a bottom cover/lid. The cover/lid is affixed toa flange-like rim with a curved end, and may be formed from aluminum ora multi-layer composite comprising paper, aluminum and/or plastic (e.g.polypropylene (PP), polyethylene (PE), polyamide (PA), polyethyleneterephthalate (PET), ethylene vinyl alcohol (EVOH), polyvinylidenechloride (PVDC), etc.).

The delivery cover/lid is sealed to the body at the curved flange-likerim, and includes a calibrated orifice or perforating means such thatthe restriction(s) created by the orifice provides elevated backpressure in the capsule during the extraction process. A filter materialmay optionally be placed between the chamber and the cover.

Additional capsule designs are disclosed in EP2690035B1. The capsuledescribed therein includes a perforated bottom wall which is stiffenedby a circular rib, a generally truncated cone or frustoconical side wallhaving a flange/rim, and a cover/lid which is affixed to the rim afterloading the capsule with a beverage ingredient.

Further capsule designs are disclosed in U.S. Pat. No. 7,543,527. Thecapsule is formed from a cylindrical or slightly tapered cup. An upperdistribution member is positioned inside the cup on an upper shoulder,proximate to the cover, to modify the flow of liquid into the cup duringbrewing. The cup further includes a lower distribution member to collectflow out of the cup during extraction of the brewed beverage. The cupand cover consist of a gas-tight, multi-layer composite film.

Methods and assemblies for preparation of food/beverage products aredisclosed by EP 1 659 909 B1. A capsule includes a bottom wall and atapered side wall with a flange extending outwardly from the cup andsidewall. The cup is typically made of a plastic material, such as EVOH,PVDC, PP, PE, and/or PA in a mono- or multi-layer construction. The bodyof the cup is sealed by a cover/lid on the flange, for example by heatsealing. The cover/lid is a perforatable material, such as aluminum,aluminum/plastic, cardboard/plastic, cardboard/aluminum/plastic, or amono- or multi-layered plastic.

Further capsule designs are disclosed by EP 2 648 579 B1. A cartridge orcapsule is supplied as a small cup with various shapes includingfrustoconical, prismatic, frustopyrimidal, etc. A side wall and bottomwall define a volume which is sealed at the end opposite the bottom wallby a sealing foil. The sealing foil is heat-sealed to a flange/rimprovided on the side wall of the cup.

Although many variations have been proposed concerning the actualcapsule part, many capsules currently on the market remain resistant tocomposting. Thus, capsules composed of a polylactic acid-based (PLA)plastic material or plastic materials called “PLA compatible” have beendeveloped. The materials called “PLA compatible” correspond to a mixtureof PLA and plant fibers. They are biodegradable and compostable. Thus,these capsules fulfill the conditions of compostability imposed by theEN 13432 standard.

However, to date no satisfactory solution has been proposed forcombining lids that are also compostable with said capsules. As usedherein, the term “compostable lid” designates a lid comprising a maximumof 5% by weight of non-compostable binder or fibers, thus meeting EN13432

This is not surprising since the limitations relating to the cover orlid are numerous. Indeed, said capsules are likely to be used in coffeemachines at pressure and temperature values for which they must bemechanically resistant.

Essentially, capsules are used in a single-serve espresso coffee machineaccording to the following process. Once the capsule is placed in itsposition, the bottom thereof is punctured. The orifices formed allow theintroduction of water, heated to a temperature of 96° C., into the bodyof the capsule at a pressure of between 10 and 12 bars. The waterfilling the capsule progressively exerts a pressure on the lid whichcomes in contact with puncturing elements arranged in the machine, suchas pins. The pressure at the time of perforation of the lid and duringpercolation is most often between 5 and 15 bars depending on theparticle size of the coffee. Once the lid has been punctured by means ofthe pins, the coffee flows into the cup. Manufacturers impose a numberof conditions in terms of the flow of coffee. In particular, there mustbe no powder in the cup. Moreover, a capsule of around 30 ml typicallydrains off in about 30 seconds. Furthermore, the flowing liquid shouldhave a color and density similar to that of foam. There are also acertain number of limitations once the coffee has flowed while thecapsule has not yet been ejected. Indeed, if the user only ejects thecapsule a few hours after the coffee has flowed out, i.e. once thetemperature of the capsule returns to ambient temperature, the capsuleshould not be deformed. Otherwise, it does not fall into the receptacleprovided for that purpose when a new capsule is inserted. The lidsshould not be delaminated.

Additionally, a compostable lid is considered satisfactory in terms ofpressure resistance when the lid does not tear when it is subjected to apressure exerted by the mixture of powder and water of between 5 and 15bars at the time of perforation of the lid and during percolation.Before the perforation, the lid must not tear under the effect of thepressure of the water rising in the capsule. After perforation, theholes from the perforation must maintain their shape and the lidmaterial should not allow large tears to propagate from the holes underthe effect of pressure. In other words, a compostable lid is needed thatis resistant to moisture and pressure so as not to tear prior to themoment it is punctured. It is also necessary to provide a lid that doesnot allow the powder to pass through when the coffee the flows out.

FR 2 991 230 A1 describes a multilayer complex combining a non-wovenmaterial of biodegradable polymer, a layer of adhesive suitable forcoming into contact with food and a cellulose fiber support, for themanufacture of molds. In particular, this document describes theadvantage of using this type of complex under the wet conditionssuitable for the implementation of said molds. Naturally, no pressurecondition is mentioned since it is not a parameter to take into accountfor this application.

The problem the invention proposes to resolve, therefore, is to devise acompostable lid for sealing a capsule, in particular a capsulecontaining coffee, which meets the conditions of use of this type of lidin coffee machines, in particular, resistance to moisture and pressure,absence of delamination, and filtering properties to prevent the passageof coffee into the cup at the moment of percolation.

Another problem that the invention proposes to resolve is also that ofimproving a lid that can be integrated into current lid manufacturingprocesses without substantial modification to said processes.

The invention provides such a compostable lid for sealing a capsule.These and other advantages of the invention, as well as additionalinventive features, will be apparent from the description of theinvention provided herein.

BRIEF SUMMARY OF THE INVENTION

In one aspect, the invention provides a compostable lid. The lid isintended to seal a beverage capsule. The lid is composed of a multilayercomplex successively comprising: a non-woven material comprising fibers,of which at least 50% by weight of the fibers are composed ofbiodegradable fibers; an adhesive layer suitable for coming into contactwith food; and a support composed of a vegetable parchment.

In some embodiments, the compostable lid is characterized in that atleast 40% by weight of the biodegradable fibers are heat-sealablefibers.

In various embodiments, the compostable lid is further characterized inthat the biodegradable fibers are selected from the group of fibersconsisting of PLA, PHA (polyhydroxyalkanoate), PHB (Poly(hydroxybutyrate)), PHB (V) (poly (hydroxybutyrate-co-hydroxyvalerate)),PBS (poly (butylenesuccinate)), biopolyesters, and cellulose fibers suchas cotton, flax, and wood fibers.

In various embodiments, the compostable lid is further characterized inthat the heat sealable fibers are selected from the group consisting ofPLA, PHA (polyhydroxyalkanoate), PHB (poly (hydroxybutyrate)), PHB (V)(poly (hydroxybutyrate-co-hydroxyvalerate)), PBS (poly(butylenesuccinate)), and biopolyesters.

In various embodiments, the compostable lid is further characterized inthat the non-woven material comprises heat-sealable fibers that have amelting point of at least about 100° C.

In some embodiments, the compostable lid is characterized in that thenon-woven material comprises 100% by weight of fibers, of which at least50% by weight are composed of polylactic acid fibers.

In some embodiments, the compostable lid is characterized in that thefibers of the non-woven material are composed exclusively of polylacticacid.

In some embodiments, the compostable lid is further characterized inthat the grammage of the non-woven material is between 5 and 100 g/m²,advantageously between 10 and 30 g/m², still more advantageously between15 and 20 g/m², and preferably on the order of 18 g/m².

In some embodiments, the compostable lid is further characterized inthat the non-woven material is a bilayer.

In some embodiments, the compostable lid is further characterized inthat the adhesive is an acrylic adhesive. The compostable lid may becharacterized in that the adhesive represents between 1 and 5 g/m²dried, advantageously between 1 and 4 g/m² dried, more advantageouslybetween 2 and 3 g/m² dried, preferably on the order of 3 g/m² dried withrespect to the surface of the multilayer complex. In general, theadhesive amount should preferably not exceed a maximum of 5% of thetotal weight of the lid.

In some embodiments, the compostable lid is further characterized inthat the grammage of the vegetable parchment layer is between 30 and 120g/m², advantageously between 50 and 100 g/m², more advantageouslybetween 60 and 80 g/m², and preferably on the order of 70 g/m².

In some embodiments, the compostable lid is further characterized inthat the vegetable parchment layer has an oxygen transfer rate less than1.5 ml/m²/day, and preferably less than 1.0 ml/m²/day, measured at anatmospheric pressure of 1.013 bar, a temperature of 23° C., and arelative humidity of 50% according to ASTM D 3895 and ASTM F 1927.

In some embodiments, the compostable lid is further characterized inthat the vegetable parchment layer has a wet burst strength measuredaccording to ISO 3689 and a dry burst strength measured according to ISO2758, and wherein the ratio of the wet burst strength to the dry burststrength is between 50 to 70 percent, preferably between 55 to 65percent.

In some embodiments, the compostable lid is further characterized inthat the vegetable parchment layer has a thickness between 60 to 150micrometers, measured according to ISO 534.

In various embodiments, the compostable lid is further characterized inthat the lid is compostable by the EN 13432 standard.

In some aspects, the invention comprises a beverage capsule includingthe compostable lid. In some embodiments, the beverage capsule containscoffee.

In some embodiments, the beverage capsule comprises a capsule body,wherein the capsule body is made of PLA or of a PLA compatible material.

In some embodiments, the compostable lid is utilized to seal a capsule,the lid being positioned in such a way that the heat-sealable non-wovenmaterial is on the surface of the lid facing the capsule.

In some embodiments, the beverage capsule is used in a single-servebeverage machine.

In some embodiments, the beverage capsule is compostable by the EN 13432standard.

In still another aspect, the invention provides a method of using thecompostable lid to seal a coffee beverage capsule. In further aspects ofthe method, the non-woven material of the compostable lid of thebeverage capsule is on the surface of the lid facing the capsule.

Other aspects, objectives and advantages of the invention will becomemore apparent from the following detailed description when taken inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings incorporated in and forming a part of thespecification illustrate several aspects of the present invention and,together with the description, serve to explain the principles of theinvention. In the drawings:

FIG. 1 is a cross-sectional representation of a lid material accordingto the present invention;

FIG. 2 is a representation of a beverage capsule including a lidaccording to the present invention; and

FIG. 3 is a cross-section of a bicomponent fiber suitable for forming alid according to the present invention.

While the invention will be described in connection with certainpreferred embodiments, there is no intent to limit it to thoseembodiments. On the contrary, the intent is to cover all alternatives,modifications and equivalents as included within the spirit and scope ofthe invention as defined by the appended claims.

DETAILED DESCRIPTION OF EMBODIMENTS

Referring to FIG. 1, the applicant has devised a complex combining anon-woven material 3 based on biodegradable and heat-sealable fibers,more particularly PLA fibers, an adhesive layer 2, and a vegetableparchment support 1, that is a suitable material for forming a lid 20for beverage capsules. The lid 20 thus obtained is resistant topressure, moisture and is easily integrated into existing capsulemanufacturing processes. Moreover, the non-woven layer 3 prevents thepassage of the powder through the lid 20 at the moment the coffee flowsinto the cup.

The lid 20 may be used to seal a capsule containing coffee. Embodimentsof a lid 20 may be particularly used to seal the coffee and beveragecapsules discussed above. Additionally, the lid 20 is suitable for usein both upright applications (that is, where the cover or lid 20 is atthe top of the capsule during brewing and extraction operations) andinverted applications (that is, where the cover or lid 20 is at thebottom of the capsule during brewing and extraction operations). In someapplications, bottom 36 may also include a second lid according to thepresent invention, which may be pierced in the same manner as lid 20.

In specific embodiments, the lid 20 is a multilayer complex successivelycomprising the non-woven material 3 wherein at least 50% of the fibersare composed of polylactic acid fibers. Adhesive layer 2 is a materialsuitable for coming into contact with food under the conditions of useof the lid 20.

According to a first characteristic, the lid 20 of the inventioncontains a non-woven material 3, at least 50% of the fibers of which arecomposed of biodegradable and heat-sealable fibers. The heat-sealablefibers typically have a melting point between 100° C. to 250° C., andmore preferably between 100° C. to 200° C.

In a preferred embodiment, the fiber non-woven material 3 are composedof at least 80% polylactic acid fibers, more preferably at least 85%polylactic acid fibers, and still more preferably at least 90%polylactic acid fibers. The PLA fibers advantageously have a diameter ofbetween 10 and 15 micrometers.

The polylactic acid (PLA) has the particular advantage of beingbiosourced, biodegradable and compostable. As used herein, “polylacticacid” and “PLA” refers to a renewable, biodegradable, thermoplastic,aliphatic polyester formed from a lactic acid or a source of lacticacid, for example, renewable resources such as corn starch, sugarcane,etc. The term PLA may refer to all stereoisomeric forms of PLA includingL- or D-lactides, and racemic mixtures comprising L- and D-lactides. Forexample, PLA may include D-polylactic acid, L-polylactic acid (alsoknown as PLLA), D,L-polylactic acid, meso-polylactic acid, as well asany combination of D-polylactic acid, L-polylactic acid, D,L-polylacticacid and meso-polylactic acid. PLAs useful herein may have, for example,a number average molecular weight in the range of from about 15,000 andabout 300,000. In preparing PLA, bacterial fermentation may be used toproduce lactic acid, which may be oligomerized and then catalyticallydimerized to provide the monomer for ring-opening polymerization. PLAmay be prepared in a high molecular weight form through ring-openingpolymerization of the monomer using, for example, a stannous octanoatecatalyst, tin (II) chloride, etc.

As also used herein, the term “biodegradable polymer” indicates that thepolymer may be broken down into organic substances by living organisms,such as by microorganisms. Biodegradable polymers may include one ormore of: polyhydroxyalkanoates (PHAs), including polylactic acid orpolylactide (PLA), as well as co-polymers of PLA and PHAs other thanPLA; biodegradable polyethylene (PE); biodegradable polypropylene (PP);biodegradable polybutane (PB); starch-based polymers; cellulose-basedpolymers; ethylene vinyl alcohol (EVOH) polymers; other biodegradablepolymers such as polybutanediolsuccinic acid (PBS); etc. In a preferredembodiment, the biodegradable non-woven described herein meets thecompostability and biodegrability standards of EN 13432.

As also used herein, the term “polyhydroxyalkanoates (PHAs)” refersbroadly to renewable, thermoplastic aliphatic polyesters which may beproduced by polymerization of the respective monomer hydroxy aliphaticacids (including dimers of the hydroxy aliphatic acids), by bacterialfermentation of starch, sugars, lipids, etc. PHAs may include one ormore of: poly-beta-hydroxybutyrate (PHB) (also known aspoly-3-hydroxybutyrate); poly-alpha-hydroxybutyrate (also known aspoly-2-hydroxybutyrate); poly-3-hydroxypropionate;poly-3-hydroxyvalerate; poly-4-hydroxybutyrate; poly-4-hydroxyvalerate;poly-5-hydroxyvalerate; poly-3-hydroxyhexanoate;poly-4-hydroxyhexanoate; poly-6-hydroxyhexanoate;polyhydroxybutyrate-valerate (PHBV); polyglycolic acid; polylactic acid(PLA), etc., including copolymers, blends, mixtures, combinations, etc.,of different PHA polymers, etc. PHAs may be synthesized by methodsdisclosed in, for example, U.S. Pat. No. 7,267,794 (Kozaki et al.),issued Sep. 11, 2007; U.S. Pat. No. 7,276,361 (Doi et al.), issued Oct.2, 2007; U.S. Pat. No. 7,208,535 (Asrar et al.), issued Apr. 24, 2007;U.S. Pat. No. 7,176,349 (Dhugga et al.), issued Feb. 13, 2007; and U.S.Pat. No. 7,025,908 (Williams et al.), issued Apr. 11, 2006, the entiredisclosures and contents of each of the foregoing documents being hereinincorporated by reference.

The term “cellulose-based polymer” refers to a polymer, or combinationof polymers, which may be derived from, prepared from, etc., cellulose.Cellulose-based polymers which may be used in embodiments of the presentinvention may include, for example, cellulose esters, such as celluloseformate, cellulose acetate, cellulose diacetate, cellulose propionate,cellulose butyrate, cellulose valerate, mixed cellulose esters, etc.,and mixtures thereof.

In general, the non-woven material 3 is a biodegradable polymer materialobtained by random arrangement of individual fibers that are interlaced.The cohesion of the fibers to each other can be enhanced, for example,by the addition of adhesive or binders (latex, polyvinyl alcohol,starch, etc.), by heating, pressure, or by bonding. Numerous methods forpreparing non-woven materials form part of the knowledge of a personskilled in the art. For example, they include methods of meltblowing,spin laying, spunbond, carding, air laying, or water laying.

In addition to PLA fibers, the non-woven material 3 can includeadditives, mineral fillers, and/or fibers from at least one biosourcedpolymer, which may be a biodegradable polymer. For example, thenon-woven material 3 can include cellulose fibers, such as cotton, flax,and wood fibers, and/or cellulose-based polymers. The incorporation ofadditives, fillers, or other fibers can make it possible to modulate themelting point of the non-woven layer 3.

In one advantageous embodiment, the cohesion of the fibers and thereforeof the non-woven material is obtained in the absence of adhesive orbinder by a manufacturing method called spunbound.

Under these conditions, the non-woven material comprises 100% by weightof fibers, of which at least 50% by weight, advantageously 100% byweight, are composed of PLA fibers.

The non-woven material can be single layer. Advantageously, it caninvolve a bilayer non-woven material. The bilayer can besingle-component, i.e. containing only one type of PLA, or bi-component,i.e. containing 2 types of PLA having different melting points.

Referring to FIG. 3, a PLA fiber suitable for forming non-woven material3 is shown. In some embodiments, PLA fibers 200 of non-woven material 3of lid 20 may have a core/shell structure, i.e. the fibers 200 arebicomponent fibers. In one embodiment, fibers 200 include a core 210containing polylactic acid (PLA-1) coated with an envelope or sheath 220containing polylactic acid (PLA-2). Core 210 has a diameter 212, andsheath 220 has a radial thickness 222. The ratio of diameter 212 toradial thickness 222 may also be altered to vary the properties offibers 200.

The non-woven material 3 may be characterized in that the PLA-1 of core210 is a copolymer of lactic acid monomer L1 and lactic acid monomer D1.The PLA-2 of sheath 220 is a copolymer of lactic acid monomer L2 andlactic acid monomer D2, whose D2 monomers rate is greater than themonomers rate D1 of PLA-1. The core 210 may further contain a polymericplasticizer.

In a preferred embodiment, the non-woven material 3 consists exclusivelyof the above-identified fibers 200. In some embodiments, the sheath 220may also contain a plasticizer.

According to another characteristic, the air permeability of thenonwoven measured according to the standard DIN 53.887 is between 3000and 5000 l/m²/s.

Finally, in practice the grammage of the non-woven material is between 5and 100 g/m², advantageously between 10 and 30 g/m², still moreadvantageously between 15 and 20 g/m², and preferably on the order of 18g/m².

According to another characteristic, the lid contains a layer ofadhesive suitable for coming into contact with food, particularly underthe conditions of use of the lid.

The adhesive suitable for food contact makes it possible to ensure thecohesion of the multilayer complex when it is exposed to a temperatureclose to or higher than the melting temperature of the PLA during theheat-sealing of the lid onto the capsule. The adhesive also enables thevegetable parchment support to be maintained on the PLA layer welded tothe capsule when the multilayer complex is in contact with the hot waterduring percolation, then during cooling.

The term “adhesive suitable for coming into contact with food”designates any type of adhesive generally used in the agro-foodindustry. However, it can advantageously be chosen from the groupcomprising acrylic adhesives, polyurethane adhesives, ethylene-vinylacetate and mixtures thereof.

In a preferred embodiment, the adhesive suitable for coming into contactwith food is chosen from among the acrylic adhesives marketed byLubrizol in the Carbobond® and Hycar® line, alone or as a mixture.

In practice, the quantity of adhesive represents between 1 and 5 g/m²dried, advantageously between 2 and 4 g/m² dried, preferably on theorder of 3 g/m² dried with respect to the surface of the multilayercomplex.

Advantageously, the adhesive layer contains a mixture of the citedacrylic latexes, in a proportion of about 1 g/m² dried, each.

According to a preferred characteristic of the invention, the support iscomposed of a vegetable parchment. The vegetable parchment is usuallypaper treated with sulfuric acid. Less commonly, zinc chloride can beused. The fibers are cellulose fibers generally chosen from amongeucalyptus fibers and resinous fibers. In practice, the acid partiallydissolves or gelatinizes the cellulose around the fibers. A cellulosicgel is formed, which is then precipitated. In a subsequent stage, thesupport is rinsed. See Mayer, Ferdinand F (May 1860). “TechnicalIntelligence—Vegetable Parchment—Papyrene”. The American Journal ofScience and Arts. XXIX (LXXXVI): 278, the entire contents of which areincorporated by reference. This treatment forms a sulfurizedcross-linked material with high density, stability, and heat resistance,and low surface energy, thereby imparting good non-stick or releaseproperties. Other types of cellulose fibers may be used to form avegetable parchments, such as cotton, flax, and wood cellulose fibers.

The support is therefore not a high density greaseproof paper or agreaseproof paper treated chemically (for example by a fluorinatedresin). The support also contains no resin obtaining a mechanicalresistance when wet.

In typical embodiments, the grammage of the vegetable parchment layer isbetween 30 and 120 g/m². In some embodiments, the grammage of thevegetable parchment layer advantageously between 60 and 80 g/m², andpreferably on the order of 70 g/m². In other embodiments, the grammageof the vegetable parchment layer is preferably between 70 g/m² and 110g/m².

The vegetable parchment layer may be characterized by both wet burststrength as measured by ISO 3689 and dry burst strength as measured byISO 2758. In order to improve resistance to pressure, the vegetableparchment will have a wet burst strength to dry burst strength ratiobetween about 50-70%, and more preferably between about 55-65%. In oneembodiment, a lid formed according to the present invention incorporatesa vegetable parchment layer available under the commercial name“SULFLEX® HPL”, which at a grammage of 70 g/m²has a wet burst strengthbetween about 180-270 kPa, a dry burst strength between about 300-400kPa, and a wet burst/dry burst ratio of about 60-67%.

In some embodiments, the vegetable parchment layer may also act as anoxygen barrier. A target oxygen transfer rate (OTR) through the lid isless than 1.5 ml/m²/day, and preferably less than 1.0 ml/m²/day(measured at an atmospheric pressure of 1.013 bar, a temperature of 23°C., and a relative humidity of 50% according to ASTM D 3985 and ASTM F1927). Some examples of measured oxygen transfer rate values of SULFLEX®vegetable parchment material are disclosed in TABLE 1 below.

TABLE 1 Oxygen transfer rate Vegetable Parchment Material (ml/m²/day)Sulflex ® - 70 g/m² 756 Sulflex ® HPL - 70 g/m² 1.4 Sulflex ® HPL - 110g/m² 0.96

The thickness of the multilayer complex, the object of the invention, istypically between 60- and 150 micrometers, and advantageously between 90and 115 micrometers, while the PLA fibers-based non-woven materialgenerally has a thickness of between 20 and 30 micrometers.

According to a particular embodiment, the compostable lid of theinvention is composed of a multilayer complex comprising successively:

-   -   a non-woven material of which 100% by weight of the fibers are        composed of polylactic acid (PLA), the grammage of which is        between 15 and 20 g/m²;    -   an adhesive layer composed of acrylic polymer suitable for        coming into contact with food, applied in a proportion of 2 to 4        g/m², dried;    -   a support composed of a vegetable parchment, the grammage of        which is between 60 and 80 g/m².

The present invention also concerns the method of preparing the liddescribed above. Said method comprises the following steps:

-   -   coating a support of a vegetable parchment with an adhesive        suitable for coming into contact with food;    -   application of a non-woven material, the fibers of which are        composed of at least 50% by weight of polylactic acid (PLA)        fibers, onto the support advantageously by association by        passing through a press;    -   drying of the multilayer complex thus obtained, advantageously        by hot air or by contact with heated cylinders.

An object of the invention is also a coffee capsule in particular,comprising a capsule per se containing the ground coffee closed with thelid as described above, the lid being positioned in such a way that thenon-woven material is facing the surface of the capsule.

In a preferred embodiment, the capsule per se is made of PLA or a PLAcompatible material. This has the advantage of being able to secure thelid to the capsule by heat-sealing insofar as the materials arecompatible (PLA or PLA compatible).

The invention also concerns the use of the previously described lid forenclosing a capsule, in particular a coffee capsule, the lid beingpositioned in such a way that the non-woven material is facing the edgeof the capsule.

The method of manufacturing said capsule comprises the following steps:

-   -   a strip is formed of a multilayer complex successively        comprising:        -   a non-woven material of which at least 50% by weight of the            fibers are composed of polylactic acid (PLA) fibers;        -   an adhesive layer suitable for coming into contact with            food;        -   a support composed of a vegetable parchment,    -   in parallel, the cells formed in a plate are filled with        individual capsules containing coffee in particular,    -   the strip is superimposed onto the plate, so that the non-woven        material is facing the plate,    -   the strip is cut in front of each of the capsules in order to        form lids,    -   the lids are heat-sealed onto the capsules.

The invention and the advantages deriving therefrom will be betterunderstood from the figures and the following example provided in orderto illustrate the invention in a non-limited manner.

Referring now to FIG. 2, a general form of a capsule 30 suitable for usewith a lid 20 is shown. FIG. 2 is generally representative of knowntypes of capsules, including without limitation: NESPRESSO® capsulesdescribed, for example, in U.S. Pat. Nos. 7,153,530 and 7,658,141, andthe capsules described in U.S. Pat. No. 7,543,527, EP 2 690 035 B1, EP 1659 909 B1, and/or EP 2 648 579 B1, each of which is incorporated byreference in its entirety. Accordingly, the capsule of FIG. 2 mayoptionally include one or more features disclosed therein, incombination with the lid 20 of the present invention.

Capsule 30 generally includes a body 32. As shown, body 32 may include aside wall 34 and a bottom wall 36 defining a central volume 44. Sidewall 34 may be cylindrical, conical, frustoconical, etc. as is generallyknown in the art and described above. Side wall may include a flange 38extending radially outward from the longitudinal axis 26 of lid 20 andcapsule 30. Flange 38 is shown including a lower surface 40 and an uppersurface 42.

Capsule 30 may include one or more filtering and/or fluid distributionunits. For example, a filter material may be affixed within the centralvolume 44 of capsule 30 by attachment of the filter material to theupper surface 42 of flange 38. The filter material may partially orcompletely cover the upper surface 42 of flange 38. In other exemplaryembodiments, a filter material may be affixed to bottom wall 36 ofcapsule 30, or to the bottom surface 24 of lid 20.

After manufacture of capsule body 32 and filling of capsule body 32 witha food item (e.g., ground coffee, tea leaves, hot chocolate mix, etc.),lid 20 is affixed to capsule 30. In typical embodiments, bottom surface24 of lid 20 is affixed to the upper surface 42 of flange 38 of capsulebody 32.

In a preferred embodiment, lid 20 is heat sealed to capsule 30, suchthat the non-woven layer 3 is contacted and heat-sealed to the capsule30. In other embodiments, lid 20 may be sealed to capsule 30 via anadhesive, laser welding, ultrasonic welding, or other methods known inthe art.

EXAMPLE

Represented in FIG. 1 is a lid 20 having a top surface 22 and a bottomsurface 24. Lid 20 is provided in the form of a multilayer complexsuccessively comprising a support 1 made of a vegetable parchment, anadhesive layer 2 suitable for coming into contact with food, and anon-woven material 3 comprising 100% by weight of fibers composed ofPLA. The multilayer complex of lid 20 is oriented with the parchmentsupport layer 1 facing outwards from the capsule, and the non-wovenlayer 3 facing inwards towards the capsule. Parchment support layer 1may optionally include printed information, such as capsule contents,manufacturer, etc.

The support 1 is preferably a vegetable parchment marketed by theapplicant under the commercial names “SULPACK®” or “SULFLEX®”. In oneexemplary embodiment, the grammage is 70 g/m².

The adhesive layer 2 is a mixture of acrylic latex in proportion ofabout 3 g/m² chosen from the line Carbobond and Hycar in a proportion ofabout 1 g/m² each.

In a preferred embodiment, the non-woven material 3 is in two layersformed exclusively of PLA fibers made by spin-laying the fibers. Thecore 210 and sheath 220 contain the same polylactic acid (PLA-1).

The lid 20 may be heat-sealed onto a beverage capsule filled with, forexample, ground coffee. The lid 20 is composed essentially ofcompostable polymers compatible with PLA. The capsule thus obtainedgenerates a flow of coffee within the time required by the manufacturers(about 10 to 60 seconds), accompanied by a foam of a quality that isequivalent to current capsules. The lid thus manufactured meets the EN13432 compostability standard and is suitable for a capsule that is alsodesigned to meet the EN 13432 compostability standard.

To test the resistance of an assembled capsule including a body 32 and alid 20, assembled capsules are placed in a NESPRESSO® Pixie machine.During percolation, the pressure within the capsule rises and reaches apeak of between about 5 to 15 bar, depending on the granularity of thecoffee grounds contained in the capsule. Lids assembled according to theinvention do not tear under pressures reaching 15 bar under theexperimental conditions therein.

All references, including publications, patent applications, and patentscited herein are hereby incorporated by reference to the same extent asif each reference were individually and specifically indicated to beincorporated by reference and were set forth in its entirety herein.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the invention (especially in the context of thefollowing claims) is to be construed to cover both the singular and theplural, unless otherwise indicated herein or clearly contradicted bycontext. The terms “comprising,” “having,” “including,” and “containing”are to be construed as open-ended terms (i.e., meaning “including, butnot limited to,”) unless otherwise noted. Recitation of ranges of valuesherein are merely intended to serve as a shorthand method of referringindividually to each separate value falling within the range, unlessotherwise indicated herein, and each separate value is incorporated intothe specification as if it were individually recited herein. All methodsdescribed herein can be performed in any suitable order unless otherwiseindicated herein or otherwise clearly contradicted by context. The useof any and all examples, or exemplary language (e.g., “such as”)provided herein, is intended merely to better illuminate the inventionand does not pose a limitation on the scope of the invention unlessotherwise claimed. No language in the specification should be construedas indicating any non-claimed element as essential to the practice ofthe invention.

Preferred embodiments of this invention are described herein, includingthe best mode known to the inventors for carrying out the invention.Variations of those preferred embodiments may become apparent to thoseof ordinary skill in the art upon reading the foregoing description. Theinventors expect skilled artisans to employ such variations asappropriate, and the inventors intend for the invention to be practicedotherwise than as specifically described herein. Accordingly, thisinvention includes all modifications and equivalents of the subjectmatter recited in the claims appended hereto as permitted by applicablelaw. Moreover, any combination of the above-described elements in allpossible variations thereof is encompassed by the invention unlessotherwise indicated herein or otherwise clearly contradicted by context.

REFERENCE SIGNS LIST

1 support

2 adhesive layer

3 non-woven material

20 lid

22 top surface

24 bottom surface

26 longitudinal axis

30 capsule

32 body

34 side wall

36 bottom

38 flange

40 lower surface

42 upper surface

44 central volume

200 fiber

210 core

212 diameter

220 sheath

222 thickness

CITATION LIST Patent Literature

U.S. Pat. No. 7,153,530

U.S. Pat. No. 7,658,141

U.S. Pat. No. 8,956,672

EP 2 690 035 B1

U.S. Pat. No. 7,543,527

EP 1 659 909 B1

EP 2 648 579 B1

FR 2 991 230 A1

U.S. Pat. No. 7,267,794

U.S. Pat. No. 7,276,361

U.S. Pat. No. 7,208,535

U.S. Pat. No. 7,176,349

U.S. Pat. No. 7,025,908

Non-Patent Literature

Mayer, Ferdinand F (May 1860). “Technical Intelligence—VegetableParchment—Papyrene”. The American Journal of Science and Arts. XXIX(LXXXVI): 278

1. A compostable lid intended to seal a beverage capsule, the lidcomposed of a multilayer complex successively comprising: a non-wovenmaterial comprising fibers, of which at least 50% by weight of thefibers are composed of biodegradable fibers; an adhesive layer suitablefor coming into contact with food; and a support composed of a vegetableparchment.
 2. The compostable lid according to claim 1, wherein at least40% by weight of the biodegradable fibers are heat-sealable fibers. 3.The compostable lid according to claim 1, wherein the biodegradablefibers are selected from the group of fibers consisting of PLA, PHA(polyhydroxyalkanoate), PHB (Poly (hydroxybutyrate)), PHB (V) (poly(hydroxybutyrate-co-hydroxyvalerate)), PBS (poly (butylenesuccinate)),biopolyesters, and cellulose fibers such as cotton, flax, and woodfibers.
 4. The compostable lid according to claim 1, wherein the heatsealable fibers are selected from the group of fibers consisting of PLA,PHA (polyhydroxyalkanoate), PHB (poly (hydroxybutyrate)), PHB (V) (poly(hydroxybutyrate-co-hydroxyvalerate)), PBS (poly (butylenesuccinate)),and biopolyesters.
 5. The compostable lid according to claim 1, whereinthe non-woven material comprises heat-sealable fibers that have amelting point of at least about 100° C.
 6. The compostable lid accordingto claim 1, wherein the non-woven material comprises 100% by weight offibers, of which at least 50% by weight are composed of polylactic acid(PLA) fibers.
 7. The compostable lid according to claim 6, wherein thefibers of the non-woven material are composed exclusively of polylacticacid (PLA).
 8. The compostable lid according to claim 1, wherein thegrammage of the non-woven material is between 5 and 100 g/m²,advantageously between 10 and 30 g/m², still more advantageously between15 and 20 g/m², and preferably on the order of 18 g/m².
 9. Thecompostable lid according to claim 1, wherein the non-woven material isa bilayer.
 10. The compostable lid according to claim 1, wherein theadhesive is an acrylic adhesive.
 11. The compostable lid according toclaim 1, wherein the adhesive represents between 1 and 5 g/m² dried,advantageously between 2 and 3 g/m² dried, preferably on the order of 3g/m² dried with respect to the surface of the multilayer complex. 12.The compostable lid according to claim 1, wherein the grammage of thevegetable parchment layer is between 30 and 120 g/m², advantageouslybetween 60 and 80 g/m², and preferably on the order of 70 g/m².
 13. Thecompostable lid according to wherein the vegetable parchment layer hasan oxygen transfer rate less than 1.5 ml/m²/day, and preferably lessthan 1.0 ml/m²/day, measured at an atmospheric pressure of 1.013 bar, atemperature of 23° C., and a relative humidity of 50% according to ASTMD 3895 and ASTM F
 1927. 14. The compostable lid according to claim 1,wherein the vegetable parchment layer has a wet burst strength measuredaccording to ISO 3689 and a dry burst strength measured according to ISO2758, and wherein the ratio of the wet burst strength to the dry burststrength is between 50 to 70 percent, preferably between 55 to 65percent.
 15. The compostable lid according to claim 1, wherein thevegetable parchment layer has a thickness between 60 to 150 micrometers.16. The compostable lid according to claim 1, wherein the lid iscompostable by the EN 13432 standard.
 17. A beverage capsule comprisingthe compostable lid according to claim
 1. 18. A beverage capsuleaccording to claim 17, wherein the capsule contains coffee.
 19. Abeverage capsule according to claim 17, wherein the capsule furthercomprises a capsule body, wherein the capsule body made of PLA or of aPLA compatible material.
 20. A beverage capsule according to claim 17,wherein the non-woven material is on the surface facing the capsule. 21.A beverage capsule according to claim 17, wherein the capsule is used ina single-serve beverage machine.
 22. A beverage capsule according toclaim 17, wherein the capsule is compostable by the EN 13432 standard.23. A method of using the compostable lid of claim 1 to seal a coffeebeverage capsule.
 24. A method according to claim 23, wherein thenon-woven material is on a surface of the lid facing the capsule.